1. Field of the Invention
This invention relates to the drainage of water off of a tile or shingle roof, and more particularly relates to a device to enhance the runoff of water passing below the roof covering at the edge of the roof nearest the facia.
2. Description of Related Art
Many buildings have tile roofs. Typically, the tiles rest upon a thin layer of sealant material such as tar paper which in turn rests on a layer of plywood decking attached to the roof trusses or rafters. When positioned on the roof, these tiles or shingles have an upper edge toward the peak of the roof and a lower edge or nose toward the eave. The upper edge is fastened to the roof either directly by nailing or some other form of direct affixation or may be formed with a lip that rests on and is supported by battens attached to the roof which run parallel to the eave line of the roof. In this way, parallel rows of tile are formed across the roof. The nose end of each tile rests atop the upper edge of the next lower tile in overlapping fashion, as seen in FIG. 1. Therefore, it can be seen that the lower edge of a tile in a parallel row is raised above the roof decking by a distance equal generally to the thickness of the next lower tile. When several rows of tile have been laid in this manner, the plane in which each respective row of tile is parallel to the others. This gives a pleasing visual appearance to the roof and allows water to run down over the tiles and off of the roof due to the overlap of tile. The lowermost row of tile (i.e.: at the eave), lacking a next lower row to support its lower edge, will lay at a non-parallel angle to the previously laid rows unless its nose is supported, creating an undesired visual appearance. For this reason, as tiles are laid down toward the edge of a roof, a "starter strip" such as rubber strip 12 in FIG. 1 has been placed along the edge of the roof at or near its lowest point to raise the lower edge of the lowermost row of tile so that the plane in which this lowermost row of tile lays will also be parallel with the other rows of tile making up the roof.
A typical starter strip is shown in U.S. Pat. No. 4,418,505 issued on Jan. 13, 1982 to Thompson. The Thompson patent provides a metal starter strip that elevates the lower edge of the tile or shingle away from the decking surface. A problem with the starter strip of Thompson which commonly arises is that water often becomes trapped by the starter strip and accumulates, commonly referred to as "pooling" or "ponding". This accumulated water invariably works its way through the sealant material and into the plywood decking layer of the roof and the eave, causing wood rot and consequent structural failure and leakage. Drain holes such as 18 in FIG. 1 are often drilled along the starter strip to allow the water to drain, but because the size of a drain hole 18 is necessarily limited by the dimensional and strength characteristics of the starter strip, the drainage holes become easily and quickly plugged by debris, rendering them useless and leaving the same ponding problem.
An additional problem exists in that the starter strip 12 typically consists of a single resilient projection extending upward from the decking material, and hence is equipped for supporting only tiles of comparatively light weight. Heavy weight tiles cause the starter strip to bend or deform, thus no longer positioning the lowermost row of tile at the desired angle. A device is needed which can support such heavy as well as light tiles and provide efficient water drainage.
In addition, no device currently available combines a flashing strip-type water deflection means for deflecting water away from the eave after said water runs off of the roof tile and/or decking surface with a tile nose riser that is strong enough to support heavy tiles and allow for efficient drainage of water out of the water ponding area.